Reusable ledger board with a nail-loosening means

ABSTRACT

A reusable ledger board adapted to be removably secured to the upwardly extending walls of a swimming pool to establish the support for a row of tiles to be attached by mortar or otherwise to the pool wall adjacent the upper edge portion thereof. The ledger board includes an elongated, relatively wide block of an elastomeric material that is flexible to permit the ledger board to conform to the contours of a pool wall and is resilient to accommodate localized deformation and stress developed in attaching the board to a pool wall. The ledger board further includes fastener mechanism including guide structure embedded within the block and extending substantially from face to face thereof. The guide structure has a passage therethrough open at one end to receive an elongated anvil effective to transmit impact force therethrough to a hardened nail within the passage and extending through a narrow channel provided therefor into contact with the pool wall. The fastener mechanism including the anvil is used in removing the ledger board from the wall by permitting lateral forces to be applied to the guide structure to rock the same and thereby loosen the nail from the wall penetrated thereby. The invention further includes a method of removably securing the ledger board to the wall, and such method contemplates confining each nail within the guide structure and delivering impact force thereto via the anvil, and subsequently imparting lateral forces to the anvil to rock the guide structure and thereby loosen the nail from the wall penetrated thereby.

Elnited States Patent 191 Stegmeier Mar. 18, 1975 1 REUSABLE LEDGER BOARD WITH A NAIL-LOOSENING MEANS [76] Inventor: William J. Stegmeier, 1021 C Shary Cir., Concord, Calif. 94520 [22] Filed: Jan. 29, 1973 [21] Appl. No.: 327,671

[52] US. Cl 52/127, 52/309, 52/720,

52/747, 249/20 [51] Int. Cl. E04g 19/00, E04g 21/00 [58] Field of Search 52/127, 309, 403, 521,

52/717, 617, 720, 749, 746, 747; l6/DIG. 33, 108, 109; 248/358 R; 249/19, 20;

Primary Eruminer-Alfred C. Perham Anorney, Agent, or FirmC. Michael Zimmerman [57] ABSTRACT A reusable ledger board adapted to be removably secured to the upwardly extending walls of a swimming pool to establish the support for a row of tiles to be attached by mortar or otherwise to the pool wall adjacent the upper edge portion thereof. The ledger board includes an elongated, relatively wide block of an elastomeric material that is flexible to permit the ledger board to conform to the contours of a pool wall and is resilient to accommodate localized deformation and stress developed in attaching the board to a pool wall. The ledger board further includes fastener mechanism including guide structure embedded within the block and extending substantially from face to face thereof. The guide structure has a passage therethrough open at one end to receive an elongated anvil effective to transmit impact force therethrough to a hardened nail within the passage and extending through a narrow channel provided therefor into contact with the pool wall. The'fastener mechanism including the anvil is used in removing the ledger board from the wall by permitting lateral forces to be applied to the guide structure to rock the same and thereby loosen the nail from the wall penetrated thereby. The invention further includes a method of removably securing the ledger board to the wall, and such method contemplates confining each nail within the guide structure and delivering impact force thereto via the anvil, and subsequently imparting lateral forces to the anvil to rock the guide structure and thereby loosen the nail from the wall penetrated thereby.

10 Claims, 6 Drawing Figures PATENTED W5 v SHEET3QF3 FIG-5 REUSABLE LEDGER BOARD WITH A NAIL-LOOSENING MEANS This invention relates to the construction of swimming pools and the like and, more particularly, to securing a horizontal row of tiles to a swimming pool wall along the upper edge portion thereof. In still more specific terms, the invention is concerned with a ledger board or the like adapted to be removably secured to the upwardly extending walls ofa swimming pool to establish the elevation for such row of tiles and to support the same as they are being secured to the pool wall.

The invention has utility, however, in various environments wherever a ledger board or the like is removably secured to a wall for some purpose, and the invention pertains specifically to a reusable ledger board and to a method of using the same. The environment of a swimming pool affords a typifying example of an environmental use of the invention, and it will be described in functional association therewith.

Considering then the construction of swimming pools as an environmental use of the invention, the technique now generally followed is to form the upwardly extending and bottom closure walls of the pool with concrete which may be poured into molds erected for this purpose but is more usually deposited by a gunite process in which the cement, water, and aggregate are mixed at a nozzle and ejected under pressure against a prepared support or backing. After the concrete has cured sufficiently, the inner surfaces of the concrete that are intended to contain water are covered with a suitable finishing material, and a horizontal deck is provided at the top of the upwardly extending pool walls to form a walkway and drainage area about the pool, and to establish an aesthetically attractive frame thereabout. The deck may be poured concrete and is often a cantilever deck that overhangs the pool walls.

Whereas in the past it was common to finish or face the water-containing concrete wall surfaces of a swimming pool with ceramic tile, material and labor costs today generally prohibit the overall use of tile facing, and a finishing coat of concrete (which is usually referred to as plaster and comprises an admixture of cement and fine aggregate) is used to face the concrete walls. However, it is desirable, if not necessary, to provide at least a single horizontal row of ceramic tile adjacent the upper edge portion of the sidewalls of a swimming pool at the elevation at which the water level in the pool is to be maintained. The reason therefor is that body oils collect along the water surface in a swimming pool and adhere to the pool walls with considerable tenacity at the water level, thereby making removal of such oils from the wall surrfaces quite difficult. The hard, substantially impervious finish of glazed ceramic tile facilitates removal of such oils and other matter, and is advantageously used in a swimming pool at this location. Such use of tile has been found practicable because the costs of setting one such row of tile is not prohibitive with reference to the advantages attributable thereto.

The tile-setting procedure now universally followed is for a tile setter to locate the highest elevation along the pool wall, patch or fill the upper edge of the pool wall to bring it to this elevation (this is not always done but should be), and then nail a wooden ledger board to the wall in a horizontal orientation a measured distance below such elevation. A suitable mortar is then prepared, spread along the upper edge portion (often referred to as a bond beam) of the concrete walls above the ledger board, and each tile block (or sheet of mosaic tile) is seated upon the ledger board and pressed into the mortar, care being taken to align each tile vertically and in planar relationship with those tiles adjacent thereto as well as horizontally. After the mortar has set, the ledger board is stripped from the wall and the surfaces thereof below the tile are covered with the aforementioned finishing material.

A number of disadvantages are inherent in the use of this technique and especially in the use of wooden ledger boards which are secured to the pool wall by specially hardened nails that are manually driven through the ledger boards and into the concrete to secure the ledger boards thereto. In this respect, the ledger boards are thin or narrow strips of wood having the requisite flexibility that enables the same to be bent into curvilinear configurations conforming to the curvatures of.the pool wall, and in the usual instance the wood employed is redwood. The cost of redwood is very high except along the West Coast of the United States, and the wood is invariably damaged if not totally destroyed in removing the same from the pool wall. Thus, it is exceptional rather than routine when the ledger boards can be reused, and any reuse thereofis limited to a very few times.

Also, the wooden ledger boards are very thin so that they do not provide an alignment surface or support surface of any significant extent, thereby making their use inconvenient at best but more significantly, making it difficult to obtain planar alignment of the tiles along a badly irregular wall surface having both extensive projections and depressions. Further, relatively long nails must be employed because they are hand-held when driven which necessitates the nails being relatively large in diameter since diameter is a function of length. The large size required for such nails thereby makes driving the same more difficult, and the damage to the wall is much greater than would be the case if the nails were thin and short. Another difficulty is that the nails must be hardened in order to enable them to penetrate concrete, thereby making them brittle, and very often the nails will shatter causing fragments in the nature of sharpnel that can injure workmen especially about their eyes.

In view of all of the foregoing, a general object of the present invention is to provide an improved ledger board or the like including fastener mechanism therefor, and an improved method of using such board or, more particularly, an improved method of removably securing a ledger board to a concrete wall or the like.

Additional objects, among others, of the invention are in the provision ofa reusable ledger board adapted to be removably secured to a concrete wall or the like and that includes an elongated block of an elastomeric material that is resilient and flexible and able to restore itself essentially to a prestressed condition; that further includes fastener mechanism for use in removably securing the ledger board and resilient elastomeric block thereof to a concrete wall component, and which fastener mechanism comprises an elongated guide structure mounted within an opening provided therefor in the resilient block and constrained against independent movement with respect thereto, and also comprises an elongated anvil slidably receivable within a passage provided in the guide structure and operative to transmit impact force derived from hammer blows against the outer end of the anvil to a nail centered within the passage and held by the guide structure in a normal orientation to the wall; and which objects are further in the provision of a method of removably securing such reusable ledger board to a concrete wall by first placing the inner face of the board thereagainst and inserting a nail into the guide structure and displacing the elongated anvil thereinto to force the point of the nail against the wall, then delivering impact force to the anvil to drive the nail into the wall and thereby secure the ledger board thereto, and finally after the ledger board has completed its function, imparting lateral force to the anvil and guide structure to loosen the nail from the wall and thereby release the ledger board therefrom.

Additional objects and advantages of the invention, especially pertaining to detailed features and characteristics thereof, will become apparent as the specification continues.

An embodiment of the invention is illustrated in the accompanying drawings, in which:

FIG. 1 is a broken perspective view illustrating a ledger board embodying the present invention secured to the bond beam of a swimming pool;'

FIG. 2 is an enlarged, broken vertical sectional view of the assemblage illustrated in FIG. 1 but with a mold form shown in position along the row of tile supported above the ledger board, and with a cantilever deck above the bond beam being illustrated by broken lines;

FIG. 3 is a broken vertical sectional view illustrating the step of securing the ledger board to the bond beam shown in FIGS. 1 and 2;

- FIG. 4 is a vertical sectional view, similar to that of FIG. 3, but illustrating the step of removing the ledger board from such bond beam;

FIG. 5 is a broken perspective view, similar to that of FIG. 1, but illustrating the ledger board in use during a modified tile-setting operation; and

FIG. 6 is a broken perspective view illustrating a completed swimming pool having tile secured thereto by use of the ledger board shown in FIGS. 1 and 2, with the pool wall below the tile being finished with a plaster coating, and with a cantilever deck having been poured in overlying relation with the bond beam of the pool.

As respects the present invention the ledger board, fastener mechanism, and method of using the ledger board and mechanism are appropriately employed in association with a large variety of wall components and especially concrete wall components irrespective of whether they are vertically disposed, horizontally oriented, or of some intermediate disposition. Accordingly, it may be said that any such wall component may be completely conventional and per se forms no part of the present invention. Therefore, for purposes hereof, the wall component shown in the drawings may be taken to be completely conventional concrete wall and, in particular, the upper end portion of the vertical wall of a swimming pool. Thus, in FIGS. 1, 2, and 6, the swimming pool wall is denoted with the numeral 10, the enlarged upper end portion thereof (referred to in the art as a bond beam) is designated with the numeral 11, and the deck which overlies the bond beam is identified with the numeral 12 (see FIG. 6).

The typifying pool wall shown in the drawings may be formed by a conventional gunite process in which wet concrete is discharged under pressure through a nozzle against a form which, to a great extent, is provided by the earthen mass bordering the cavity therein within which the pool is to be constructed. In FIG. 6, a portion of the earthen mass is shown and is denoted with the numeral 14. Since concrete is a relatively rough and porous material, it is substantially standard practice in the construction of a swimming pool to provide a row of ceramic tile along the pool wall at the water level so that body oils and similar matter collecting along the surface of the water will tend to collect onto the hard finished surface of the tile from which it is readily removed rather than along the concrete from which its removal would be very difficult. A row of tiles is shown in FIG. 6, and it constitutes a plurality of individual tiles 15 disposed in side-by-side adjacency. The spaces between successive tiles is grouted in a conventional manner, and the inner surface of the pool wall 10 below the row of tiles 15 is covered with a finishing coating of concrete that is usually referred to as plaster and is identified with the numeral 16. The deck 12 shown is a cantilever deck and is known as such because the inner edge thereof overhangs the inner surface of the pool wall 10 and row of tile 15 secured thereto.

Referring now to FIGS. 1 through 4, a ledger board embodying the present invention is shown in association with the pool wall 10 and bond beam 11 thereof, and the ledger board is denoted in its entirety with the numeral 17. The ledger board 17 is adapted to be removably secured to the wall 10 so that it may be reused repeatedly, thereby reducing the cost of tile setting along a pool wall and, at the same time, improving the quality of the row along the wall and also making the setting thereof more convenient. In general terms, the reusable ledger board 17 includes a block .18 of elastomeric material and fastener mechanism 19 cooperatively arranged therewith.

The block 18 has transversely spaced inner and outer surfaces 20 and 21 the first of which is adapted to be disposed in contiguous juxtaposition with the wall 10, as shown in each of FIGS. 1 through 4. In the form shown, the block 18 is polygonal in transverse section (see FIG. 1) and, more specifically, it is of rectangular shape. Accordingly, the inner and outer surfaces 20 and 21 are substantially parallel, and they are interconnected by substantially parallel top and bottom surfaces 22 and 24. The block 18 is solid, and it is quite thick in the transverse dimension so as to provide a substantial mass of resilient material. That is to say, the block 18 may be formed of any suitable elastomer providing resilience that enables the block to be subjected to localized deformation or stress of the types shown in FIGS. 2 and 4, and which will restore itself to essentially its prestressed configuration when the force causing the same is removed. Various materials afford such properties, and a specific example thereof is a synthetic plastic such as polyethylene foam. The precise dimensions of the block 18 may vary greatly, but by way of a numerical exemplification, a typical block may be approximately six inches in height, two inches in width from face-to-face thereof, and may be eight to ten feet long although any required length can be provided.

The block 18 is provided at longitudinally spaced locations therealong with the aforementioned fastener mechanisms 19, as shown best in FIG. 1. For this purpose, the block has a plurality of longitudinally spaced and transversely oriented openings 25 therein (see FIG. 3 in particular) that extend essentially between the faces and 21. Each fastener mechanism includes guide structure 26 mounted within the associated opening 25, and each such guide structure has an axially extending passage 27 therein open at its opposite end adjacent the outer surface 21 of the block 18, as shown at 28. In the embodiment of the invention illustrated, the guide structure 26 is an elongated cylindrical tube with the outer end thereof turned laterally to provide a lateral projection 29 in the form of an annular flange. Intermediate its ends, the tubular guide structure may be equipped with a plurality of barbs 30 adapted to be embedded within the block 18. The flange 29 and barbs 30 comprise means for constraining the guide structure against movement relative to or independently of the block 18 and, in this reference, the flange 29 constrains the guide structure against axial movement toward the surface 20 independently of the block 18 and the barbs 30 constrain the guide structure against independent movement in the opposite direction. It will be apparent that other means may be employed to constrain the guide structure against independent movements relative to the block 18 including an adhesive bond between these components.

As seen best in FIG. 3, the tubular guide structure 26 is slightly shorter than the transverse dimension of the block 18 between the surfaces 20 and 21 thereof, thereby enabling the block to be stressed when the guide structure is displaced axially toward the surface 20, as shown in FIG. 2 and as will be explained in detail hereinafter. A plug 31 is secured to the guide structure 26 adjacent the inner end thereof, and it has an aperture therein in the form of a narrow channel 32 generally coaxial with the passage 27 and dimensioned to pass the shank 34 of a nail therethrough. The plug 31 has an inner face 35 that is adapted to abut the concrete wall 10, as shown in FIG. 2. The plug 31 also has an interior face 36 against which the head 37 of the aforementioned nail is driven to force the inner face 35 of the plug toward abutment with the wall 10. The inte rior face 36 of the plug is tapered toward the channel 32, and it is advantageously cone-shaped so that the shank and point of the nail are necessarily directed into the channel 32 irrespective of the orientation of the nail within the passage 27 of the guide structure. The plug 31 is relatively wide or thick along the axis of the passage 27 so as to be coaxially circumjacent a substantial length of the nail shank 34 which is advantageous in loosening the nail from the frictional grip of the concrete wall 10 when it is desired to remove the ledger board therefrom, as shown in FIG. 4 and as will be described hereinafter.

In the structural configuration being considered, the plug 31 is located within the passage 27 adjacent the inner end thereof, and it forms a closure therefor. The plug is fixedly secured to the guide structure so as to prevent relative axial displacements therebetween, and any suitable means may be used to effect the requisite constraint between the plug and guide structure such as a sweat fit, welding, pinning, and other comparable and well known techniques. The inner surface 35 of the plug 31 may be relieved slightly adjacent its outer extremities so as to facilitate articulation or angular displacements thereof in releasing the nail from the wall 10, as depicted in FIG. 4. That is to say, the guide structure 26 is laterally rockable against the resilience of the block 18 to loosen the nail and thereby release the ledger board 17 from the wall 10, and the slight relief of the plug wall 35 facilitates the rockability 0f the guide structure.

The fastener mechanism 19 further includes an anvil 38 that is axially elongated and is slidably receivable within the passage 27. The anvil 38 is operative to transmit impact force to the nail, as shown in FIG. 3, to drive the same into the concrete wall component 10. The anvil has a greater length than that of the passage 27 so as to project therefrom for the purpose of receiving hammer blows imparting impact force thereto which is then transmitted to the nail. The anvil also serves as a lever to rock the guide structure 26 and plug 31 secured thereto for loosening the nail and releasing the same from the concrete wall component, as previously explained. The anvil 38 is a heavy member relative to the nails 34, 37 and substantially exceeds the weight thereof, thereby effectively transmitting impact force to the nails for driving the same into the concrete wall in an efficient manner. The anvil may be an elongated steel bar or rod, and the ends thereof may be relieved or frusto-conical, as shown at 39 and 40 so that either end of the anvil may be inserted into the passage 27 of the guide structure and engage the head 37 of a nail therein without directly abutting the interior sur face 36 of the plug 31 when the nail has been driven into the wall 10 to its maximum extent, as shown in FIG. 2.

The nails 34, 37 are conventional hardened nails used for penetrating concrete components to secure ledger boards and other elements thereto. Since it is required that nails of this type be hardened to enable them to penetrate concrete, they are very brittle, as explained hereinbefore, and have a tendency to shatter. The nails used in association with the ledger board 17 may be both shorter and narrower than the nails heretofore required to secure conventional wooden ledger boards to concrete walls, and they can be reused because of the effective manner in which they are driven into an associated concrete wall and subsequently removed therefrom. The nails are conventional elements, however.

The method involved in removably securing the ledger board 17 to a concrete wall or the like includes placing the inner face 20 of the block 18 against the wall 10 at the desired elevation therealong and at the requisite orientation which, in the case of a swimming pool, is a condition of horizontal alignment. The block 18 may be manually held or otherwise maintained in the proper position until the block is secured to the wall by nails 34, 37. Nails are then inserted into the respective passages 27, and the anvil 38 is displaced into one such passage 27 to force the point of the associated nail through the aperture or channel 32 and against the surface of the concrete wall 10, as illustrated in FIG. 3. Such positioning of the anvil 38 against the head 37 of a nail is a simple manual procedure since the anvil is freely slidable within any passage 27.

Next, impact force is delivered to the outer end of the anvil 38 to drive the nail into the wall 10 and thereby secure the block 18 thereto. The impact force delivered to the anvil 38 is ordinarily derived from striking the anvil with a heavy hammer, and one or several such blows may be required to effect adequate penetration of the wall by the nail. Usually, clean sharp penetration of the wall 10 is effected by the nail because it is always oriented at right angles to the wall surface, and because massive blows may be delivered to the nail without introducing the hazards usually incident to nail shattering and without the danger that the blow will be offset from the axis of the nail.

As respects orientation of the nail, the inner surface 20 of the block 18 is a generally flat or planar surface (although the block may be formed into curvilinear configurations, as shown in FIG. 1), and the axis of the opening 25 in the block and coincident axis of the guide structure 26 and passaage 27 therethrough are essentially normal to the inner surface 20 and, therefore, substantially normal to the surface of the wall 10. Further, the axis of the nail shank 34 is also necessarily normal to the wall because it is confined within the channel 32 through the plug 31 and which channel has its axis substantially coincident with that of the passage 27 and opening 25. Thus, once the inner surface of the block 18 is pressed into intimate engagement with the wall 10, the channel 32 and any nail passing therethrough are oriented automatically in a normal disposition to the wall 10. As previously explained, the nail is automatically aligned with the channel 32 and guided thereinto as the anvil 38 is displaced into the guide structure passage 27 because of the cone-shaped configuration of the interior face 36 of the plug 31.

As respects penetration of the concrete wall 10 by the nail 34, 37, it has been documented that penetration of a concrete mass by a nail-like object is accomplished more effectively and efficiently by delivering heavy blows (i.e., high foot-pound values) to the object in contrast to delivery thereto ofa large number oflighter blows. Since the nail is confined in a fixed position, the anvil 38 is similarly confined in a spacially fixed position, and because the anvil is accurately aligned with and positively engages the nail head 37, the magnitude of any blow delivered to the outer end of the anvil by manual manipulation of a heavy hammer may be as large as a workman can conveniently delivertotally unrestricted by the fear that the nail will move and the blow glance therefrom or that he will be injured by fragments from a shattering nail. The massive character of the anvil 38 relative to the nail 34, 37 results in an efficient transmission of impact force through the anvil to the nail head 37 and also reduces any tendency toward rebound or bouncing of the anvil from the nail. Should a nail occasionally shatter, the fragments will not injure adjacent workmen because they are confined by and within the block 18 and guide structure 26.

This arrangement also permits use of shorter nails and smaller nails than is usually required because of the clean penetration of the concrete wall 10, as previously explained. This is advantageous for several reasons: first, less damage is caused to the concrete wall 10 as a result of the smaller diameters of the nails and as the result of the shorter lengths thereof; second, because less damage occurs to the nails, thereby permitting reuse thereof which reduces cost; and third, because smaller, shorter nails are much less expensive initially than larger, longer nails which is of consideration in commercial environments were large numbers of nails are used since hardened nails for use with concrete are far more expensive than common nails.

As each nail is driven into the wall 10, the nail head 37 ultimately engages the interior face 36 of the plug 31, whereupon continued penetration of the nail displaces the plug and guide structure 26 toward the wall and ultimately into engagement therewith, as illustrated in FIG. 2, provided that the nail is driven to its point of maximum penetration. As previously noted, the guide structure 26 is somewhat shorter than the transverse width of the block 18 (see FIG. 3) so that any displacement of the guide structure toward the wall 10 necessarily deforms or locally stresses the block 18, as is evident in FIG. 2. That is to say, the guide structure 26 is constrained against movement independently of the block 18 because of the presence of the flange 29 and barbs 30 so that inward displacement of the guide structure toward the wall 10 is necessarily effected against the resilience of the block 18. Such cooperation of the guide structure with the block 18 is advantageous in that it causes the inner surface 20 of the block to be held in tight contiguous juxtaposition with the wall 10. It might be noted that the relative dimen sions of the guide structure 26 and block 18 need not be as great as the exaggerated illustration in FIGS. 2 and 3, and it can be varied to suit individual needs or preferences.

After the ledger board 17 has been secured to the wall 10 and used to position the tile 15 therealong (as explained hereinafter), it can be removed from the wall without damage and in a manner permitting reuse thereof, and by means ofa convenient and very simple procedure. In this respect, and referring to FIG. 4 in particular, all that is required is for a workman to insert the elongated anvil 38 successively into the passages 27 of the guide structures 26 and then impart lateral force to the anvil to rock the guide structure and associated nail to loosen the latter from the wall and thereby release the ledger board therefrom. Such lateral force application to the anvil 38 is shown in FIG. 4 which also illustrates the rockability of the guide structure 26. It should be noted that the lateral displacements of the anvil 38 and guide structure 26 are exaggerated somewhat in FIG. 4 for illustrative purposes, and since concrete has very little compressibility and resilience, the slightest lateral displacement of the nail shank 34 is adequate to loosen the same from the grip of the concrete wall.

It is not critically essentially that the inner face 35 of the plug 31 be in intimate contact with the surface of the wall 10 in order that the nail be displaced laterally to loosen it from the grip of the wall. However, if the surface 35 of the plug does so engage the wall 10 at the time that lateral force is applied to the anvil 38, the plug becomes somewhat ofa fulcrum to augment or enhance the force application to the anvil 38 and thereby facilitate loosening of the nail shank 34 from the wall, as seen in FIG. 4. In any case, the nails 34, 37 are successively loosened as the workman moves from one fastener structure 19 to another, and after each nail has been released from the wall, the entire ledger board 17 is simply lifted or withdrawn therefrom if it has not already begun to sag as the supports therefor are released.

As previously stated, the ledger board 17 may be used in many environments but is particularly suited for use in mounting tiles 15 along the upper edge portion of the sidewall of a swimming pool. This use of the ledger board is shown in the drawings, and a brief description thereof will be made with particular reference to FIGS. 1 and 2. The ledger board 17 will first be secured to the pool wall 10 generally along the bond beam 11 thereof at the elevation required for the particular tile size being used. Although tiles of various sizes can be employed, a typical size is 6 X 6 inches, and in this event, the upper surface 22 of the block 18 will be located approximately 6 inches (slightly in excess thereof) below the upper surface 41 of the bond beam 11. In the tile-securing system shown in FIGS. 1 and 2, the upper edge portion of the bond beam 11 is trimmed back at an angular disposition, as shown at 42, for the purposes explained in detail in my copending patent application Ser. No. 299,209 filed Oct. 20, 1972. A succession of elongated lower tile holders 44 having a U-shaped opening 45 therealong is secured to the block 18 along the upper surface 22 thereof as by means of nails 46 inserted through openings provided therefor in a plurality of spaced apart cars 47 projecting outwardly from the holder 44 at the bottom thereof. It will be evident that the holder 44 is disposed along the block surface 22 at a location providing the proper location for the tiles 15. Thereafter, the tiles are inserted into the openings 45 in longitudinal succession, as shown in FIG. 1. The upper surface 22 thus provides a planar reference surface for positioning the tiles 15.

Next, an elongated longitudinally extending upper tile holder 48 having an inverted generally U-shaped opening 49 therein is positioned along the upper edges of the tiles 15 in the manner illustrated. The holder 48 has an upwardly extending T-shaped anchor 50 that becomes embedded within the deck 12 after pouring thereof, as is indicated in FIG. 2. Projecting from the anchor the tile holder 48 and form 56. Thereafter, a concrete mass is poured over the upper surface 41 of the bond beam 11 and against the mold form 56 which serves to confine the concrete mass until it cures into the deck 12 and also imposes the desired configuration along the inner exposed edge portion of the deck that overhangs the tiles 15. After the deck 12 has cured suf' ficiently to be self-sustaining, the form 56 is stripped therefrom which leaves the configuration of a finished pool, as shown in FIG. 6 after the coating 16 has been added to the pool wall below the tiles 15 and in substantial alignment therewith.

The tile holder 48 becomes a part of the permanent pool installation, and has at least two important functions one of which is serving as a type of hider strip or cover that keeps the upper edge of the tiles 15 covered even though the deck 12 may shift upwardly with respect thereto because of thermally-induced expansions and contractions of the deck, earth movements, etc.; and a second of which is that it serves as a water stop that inhibits pool water from entering the crack be tween the deck 12 and upper surface 41 of the bond beam 11. The mastics 57 and 58 cooperate with the holder 48 in the latter function of a water stop or barrier by providing a stretchable member uniting the previously-poured or old bond beam 11 and mass 55 with the subsequently-poured or new deck 12. The anchor 50 also contributes to the water-inhibiting function of the holder 48 and mastic in being anchored to the deck 12 which causes the holder 48 to move therewith relative to the tiles 15.

The form 56 may be fabricated from a synthetic plastic foam such as polystyrene, and although it forms no part of the present invention, details thereof may be obtained in my copending patent application Ser. No. 76l,726, filed Sept. 23, 1968. Analogously, the holder components 44 and 48 form no part of the present invention and are shown to a great extent in diagrammatic form. Should details concerning such holders be 18 desired, they may be found in my copending patent application Ser. NO. 299,208, filed Oct. 20, I972.

A somewhat modified use of the ledger board 17 is shown in FIG. 5 in the sense that the tiles '15 are secured to the pool wall in a slightly different manner, one that is standard and conventionally used. Since the ledger board 17, tiles 15, and form 56 are allidentical to those heretofore described, the same numerals are used to identify the same and the appropriate components thereof. The pool wall and bond beam are slightly different than those heretofore described in detail but correspond thereto in their essential particulars. Accordingly, the primed form of the same numerals are used to identify the respectively corresponding parts of the pool wall and interconnection of the tiles 15 therewith.

The ledger board 17 is secured to the pool wall 10 in precisely the same manner heretofore described. The edge 42 of the bond beam 11 is generally vertical rather than being cut back, and the tiles 15 are secured in place by a thin layer 55 of mortar that is troweled onto the pool wall and the tiles l5 pressed thereagainst in a manner standard in theart and well known for many years. The upper surface 22 of the ledger board 17 serves as the vertical support for the tiles during curing thereof and thereby orients and maintains the same at a proper location until the mortar 55 cures.

Accordingly, no upper and lower holders are required for the tiles 15, and after the mortor 55' has cured sufficiently, the form 56 for the cantilever deck is secured to the tile either before or after the ledger board 17 is removed. Ordinarily, a combination water stop and hider strip 48 is placed over the upper edges of the tiles 15 with a portion of the strip projecting downwardly intermediate the tile and form 56. A layer of mastic 57 is provided along the mergence of the water stop and form so as to interconnect the same, as previously explained. Usually an additional strip of mastic 58 is poured along the juncture of the water stop 48 and upper surface 41 of the bond beam to interconnect these components. Thereafter, a concrete deck-forming mass of concrete is poured over the surface of the bond beam 41 and against the form 56, as previously explained. Details concerning the component 48 and cooperative presence of the mastics 47' and 58' may be obtained, for example, from my issued U.S. Pat. No. 3,605,357.

The ledger board 17 is flexible as well as being resilient, and although tending to restore itself to a neutral condition, it is readily bent or flexed into curvilinear configurations to enable it to conform to the configurations of a pool wall. This characteristic of the ledger board is illustrated in FIG. 1 in which a curved section of a pool wall is illustrated, and the flexibility is also suggested in FIG. 4 that depicts the guide structure 26 in an angular disposition in which the block 18 is elastically deformed. The ledger board can be provided in any thickness desired, and the substantial thickness shown in the embodiment of the invention being considered is a substantial convenience irrespective of which of the two techniques described are used to secure the tiles 15 to the pool wall. Advantages of using smaller, shorter nails to secure the ledger boards in place have been noted hereinbefore, and among such advantages are the fact the smaller nails are much easier to drive than larger nails, and shorter nails are also stronger than longer nails in the sense that they are not as easily bent as they are driven. The reusability of the ledger boards is a substantial economic advantage and therefore contributes to the desirability of using the same.

Once the ledger board has been secured to the proper elevation, very precise planar positioning of the tiles is accomplished by simply snapping a chalk line along the upper surface 22 of the thick board at a measured distance from the bond beam sufficient to account for all bowing and other irregularities therealonng, and then aligning the support 44 (or lower edges of the tiles, as the case may be) with such chalk line. The tiles are made plumb in a conventional manner by use of a level. In nailing the ledger board to the bond beam, the resilient compressibility of the ledger board enables the workman to feel the nail move toward full penetration, thereby enabling him to stop short of unnecessary blow delivery. In this frame of reference, the dimensional example of ledger board noted hereinbefore may have a density of about 2 to 2 A pounds per cubic foot, but this specific range is not critical.

While in the foregoing specification an embodiment of the invention has been set forth in considerable detail for purposes of making a complete disclosure thereof, it will be apparent to those skilled in the art that numerous changes may be made in such details without departing from the spirit and principles of the invention.

What is claimed is:

l. A reusable ledger board adapted to be removably secured to a concrete wall and the like, comprising: an elongated block of elastomeric material having an upper surface defining a planar reference surface, and transversely spaced inner and outer surfaces the first of which is adapted to be disposed in contiguous juxtaposition with such wall; said block having a plurality of longitudinally spaced and transversely oriented open ings therein extending essentially between said faces; and fastener mechanism including guide structure mounted within each of said openings having an axially extending guide passage open at its outer end adjacent the outer surface of said block adapted to slidably receive an anvil therein and an aperture adjacent its inner end to pass the shank of a nail therethrough as it is driven into such wall by impact force transmitted through an anvil received within said passage, said guide structure being laterally rockable against the resilience of said block to loosen such nail from the con crete wall and thereby release said ledger board therefrom.

2. The ledger board of claim 1 and further comprising means constraining said guide structure against axial displacements independently of said block, whereby axial movement of said guide structure is resisted by the resilience of said block.

3. The ledger board of claim 2 in which said means includes a lateral projection carried by said guide structure adjacent the outer surface of said block.

4. The ledger board of claim 2 in which said guide structure terminates within said block a spaced distance inwardly from the inner surface of said block, said guide structure being axially displaceable against the resilient inhibition of said block toward abutment of its inner end with such wall as such nail is driven thereinto so that said block is then maintained under stress with the inner surface thereof being constrained in tight engagement with such wall by a positive force occasioned at least in part by the resilient deformation of said block.

5. The ledger board of claim 1 in which said guide structure is an elongated tube equipped adjacent its inner end with a plug having a narrow channel theethrough defining the aforesaid aperture and being generally coaxial with said passage, said plug having an inner face adapted to substantially abut such wall and having also an interior face against which the head of such nail is driven to force said inner face toward abutment with such wall, said interior face being tapered toward said channel so as to guide the shank of such nail thereinto.

6. The ledger board of claim 5 in which said fastener mechanism further includes an elongated anvil slidably received within said passage and operative to transmit impact force to such nail to drive the same into such wall, said anvil being of greater length than said passage so as to project therefrom to receive hammer blows imparting impact force thereto and also serving as a lever to rock said guide structure as aforesaid.

7. The ledger board of claim 6 in which said plug is relatively wide along the axis of said passage so that said channel is coaxially circumjacent a substantial length of the shank of such nail, thereby resisting bending of such shank during rocking ofsaid guide structure to loosen a nail from such wall.

8. The ledger board of claim 5 and further comprising means constraining said guide structure against axial displacements independently of said block, whereby axial movement of said guide structure is resisted by the resilience of said block; in which said guide structure terminates adjacent the inner end thereof a spaced distance inwardly from the inner surface of said block, said guide structure being axially displaceable against the resilient inhibition of said block toward abutment ofits inner end with such wall as such nail is driven thereinto so that said block is then maintained under stress with the inner surface thereof being constrained in tight engagement with such wall by a positive force occasioned at least in part by the resilient deformation of said block.

9. The ledger board of claim 8 in which said block is polygonal in transverse section and constitutes a resiliently compressible synthetic plastic foam material; in which said plug is relatively wide along the axis of said passage so that said channel is coaxially circumjacent a substantial length of the shank of such nail, thereby resisting bending of such shank during rocking of said guide structure to loosen a nail from such wall.

10. The ledger board of claim 9 in which said fastener mechanism further includes an elongated anvil slidably receivable within said passage and operative to transmit impact force to such nail to drive the same into such wall, said anvil being of greater length than said passage so as to project therefrom to receive hammer blows imparting impact force thereto and also serving as a lever to rock said guide structure as aforesaid. 

1. A reusable ledger board adapted to be removably secured to a concrete wall and the like, comprising: an elongated block of elastomeric material having an upper surface defining a planar reference surface, and transversely spaced inner and outer surfaces the first of which is adapted to be disposed in contiguous juxtaposition with such wall; said block having a plurality of longitudinally spaced and transversely oriented openings therein extending essentially between said faces; and fastener mechanism including guide structure mounted within each of said openings having an axially extending guide passage open at its outer end adjacent the outer surface of said block adapted to slidably receive an anvil therein and an aperture adjacent its inner end to pass the shank of a nail therethrough as it is driven into such wall by impact Force transmitted through an anvil received within said passage, said guide structure being laterally rockable against the resilience of said block to loosen such nail from the concrete wall and thereby release said ledger board therefrom.
 2. The ledger board of claim 1 and further comprising means constraining said guide structure against axial displacements independently of said block, whereby axial movement of said guide structure is resisted by the resilience of said block.
 3. The ledger board of claim 2 in which said means includes a lateral projection carried by said guide structure adjacent the outer surface of said block.
 4. The ledger board of claim 2 in which said guide structure terminates within said block a spaced distance inwardly from the inner surface of said block, said guide structure being axially displaceable against the resilient inhibition of said block toward abutment of its inner end with such wall as such nail is driven thereinto so that said block is then maintained under stress with the inner surface thereof being constrained in tight engagement with such wall by a positive force occasioned at least in part by the resilient deformation of said block.
 5. The ledger board of claim 1 in which said guide structure is an elongated tube equipped adjacent its inner end with a plug having a narrow channel theethrough defining the aforesaid aperture and being generally coaxial with said passage, said plug having an inner face adapted to substantially abut such wall and having also an interior face against which the head of such nail is driven to force said inner face toward abutment with such wall, said interior face being tapered toward said channel so as to guide the shank of such nail thereinto.
 6. The ledger board of claim 5 in which said fastener mechanism further includes an elongated anvil slidably received within said passage and operative to transmit impact force to such nail to drive the same into such wall, said anvil being of greater length than said passage so as to project therefrom to receive hammer blows imparting impact force thereto and also serving as a lever to rock said guide structure as aforesaid.
 7. The ledger board of claim 6 in which said plug is relatively wide along the axis of said passage so that said channel is coaxially circumjacent a substantial length of the shank of such nail, thereby resisting bending of such shank during rocking of said guide structure to loosen a nail from such wall.
 8. The ledger board of claim 5 and further comprising means constraining said guide structure against axial displacements independently of said block, whereby axial movement of said guide structure is resisted by the resilience of said block; in which said guide structure terminates adjacent the inner end thereof a spaced distance inwardly from the inner surface of said block, said guide structure being axially displaceable against the resilient inhibition of said block toward abutment of its inner end with such wall as such nail is driven thereinto so that said block is then maintained under stress with the inner surface thereof being constrained in tight engagement with such wall by a positive force occasioned at least in part by the resilient deformation of said block.
 9. The ledger board of claim 8 in which said block is polygonal in transverse section and constitutes a resiliently compressible synthetic plastic foam material; in which said plug is relatively wide along the axis of said passage so that said channel is coaxially circumjacent a substantial length of the shank of such nail, thereby resisting bending of such shank during rocking of said guide structure to loosen a nail from such wall.
 10. The ledger board of claim 9 in which said fastener mechanism further includes an elongated anvil slidably receivable within said passage and operative to transmit impact force to such nail to drive the same into such wall, said anvil being of greater length than said passage so as to project therefrom to rEceive hammer blows imparting impact force thereto and also serving as a lever to rock said guide structure as aforesaid. 